Mechanical movement



. J. D. DURKEE 2,680,970

June' 15, 1954 MECHANICAL MOVEMENT 2 Sheets-Sheet 1 Filed July 28. 1952 I Jar/m1). 01mm zfiw I a, f ATTORNEYS June 15, 1954 .J. D. DURKEE' MECHANICAL MOVEMENT Filed July 28, 1952 2 Sheets-Sheet 2 INVENTOR Jammy flflurlfiee W 4m W ATTORNENS' Patented June 15, 1954 UNITED STATES ATENT OFFICE MECHANICAL MOVEMENT James D. Durkee, rect and mesne Arlington, Va., assignor, by diassignments, to Dualex Corpo- 8 Claims. 1

The present invention relates to mechanism for rapidly moving and accurately positioning a mechanical element in any of a plurality of prescribed positions. Ihe invention is or" general utility, but by way of example of one field of use reference may be made to the positioning of a printer wheel of a telegraphic typewriter. A printer wheel for a telegraphic typewriter must be properly positioned to present the desired character to the inked ribbon and the paper. The positioning must be precise for neatness of the typewritten material. The movement of the printer wheel from one prescribed position to another must occur very rapidly in order for the typewriter to be capable of high speed. There are many other fields of utility for mechanisms capable of rapidly and precisely positioning a mechanical element in any of a plurality of desired positions.

One of the primary objects of my invention is to provide a mechanical linkage which is capable of rapidly and accurately positioning a mechanical element in any one of a number of desire-cl positions. Another object of the invention is to provide such a mechanism which is extremely simple so that it can be produced economically and so that there is a minimum of expense for maintenance or repair. Still another object of the invention is to provide such a mechanism in combination with a plurality of motors or drive means, which motors or drive means are identical in order to reduce costs and to simplify repairs. Still another object of the invention is to provide mechanism of the type described in which the mechanical element to be positioned has an assigned neutral position which is intermediate its other positions. The mechanical element can be moved from its neutral position to any of its other positions by traveling through a shorter path than would be the case if the elements assigned neutral positions were otherwise placed. Still another object of the invention is to provide mechanism of the type described which provides for relatively slow acceleration and/or deceleration of the mechanical element.

The foregoing and other objects and advantages of the invention will be more fully understood by reference to the following description taken in connection with the accompanying drawing, wherein:

Figure 1 is a front elevational view of mechanism embodying my invention arranged to corn trol the movement of a printer Wheel, the mechanism and the printer wheel being shown in the neutral position;

Figure 2 is a front elevational view of the apparatus shown in Figure 1 but illustrating the printer wheel moved to its extreme position in one direction from the neutral position;

Figure 3 is a front elevational View of a modifled form of apparatus embodying the invention; and

Figure 4 is a front elevational view of still another embodiment of the invention.

The arrangement illustrated in Figures 1 and 2 includes a printer wheel 6 having a type bar 1' thereon. The type bar I carries a plurality of printing characters, not shown, which are circumferentially spaced and which are intended to be presented selectively to a printing zone which is diagrammatically indicated by the reference numeral 8. The printing wheel must be oscillated to present the desired printing characters to the printing zone and this oscillatory movement must occur rapidly in order that the machine may' print at high speed. The positioning of the printer wheel must be precise for each of its angular positions in order that the printed characters will be neatly and accurately disposed on the paper.

The printer wheel is provided with a fixed axis of rotation 9. A radially extending slot it is provided in the printer wheel. This slot receives a pivot pin l l which is free to slide therein. The pivot pin l l pivotally connects the ends or" a pair of actuator links 12 and I 3. The opposite end of the actuator link I2 is pivotally connected to a base link it while the actuator link 13 is similarly connected to a base link I5. The base links it and i5 are independently oscillatable about a fixed axis I 6. In this form of the invention the base links H! and I5 are independently oscillatable about the same fixed axis, although in forms of the invention hereinafter described these links are oscillatable about axes which are not coincident.

The base link i i is provided with a stop member il' which limits its outward movement. A tension spring member I8 resiliently biases the base link is into position against the stop mem. ber ii. The base link [5 is provided with a similar stop member l9 and a tension spring member 28. The stop members I? and i9 and the spring members It and 20 determine definite normal positions for the base links it and IE, to which those links will turn when permitted to do so.

Figure 1 illustrates the base links it and I5 in their normal positions. Under such circumstances the printer Wheel 6 occupies a definite position which may be termed its neutral position. In this neutral position one printin character may be presented to the printing zone 8, and it is unnecessary to oscillate the printing wheel 5 to print such character. Figure 2 of the drawin illustrates the condition of the mechanism when it has been actuated to move the printer wheel to its extreme position in a counterclockwise direction. The base link I 5 still occupies its normal position against the stop member l9, but the base link Hi has been oscillated to the position shown in the drawing. The pivot pin i i, engaging as it does the Walls of the slot HP, has caused the printer wheel to oscillate to the position shown in Figure 2. It will be apparent from an inspection of Figures 1 and 2 that a lesser movement of the base link M would re suit in a lesser extent of oscillation of theprinter wheel 6 in the counterclockwise direction. It will also be apparent from an inspection of these figures that movement of the base link l5 awayfrom its stop member 29 will cause oscillation of the printer wheel 5 in a clockwise direction, the extent of such oscillatory movement of the printer wheel being dependent on the extent ofmovement of the base link i5.

Means for efiecting oscillatory movement of the base links is and i5 are illustrated as identical solenoids 25 to 28; inclusive. The solenoids 2i to 2%, inclusive, are positioned'along the base link it at different distances from the fixed axis it. The solenoids 25 to 28, inclusive, are positioned along the base link l5 at different distances from the fixed axis l6. Figure 2 illustrates the solenoid 2! as being energized. Its plunger has engaged the base link it and, since the solenoid 25 is positioned near the axis it, the extent of movement of thebase link it has been greater than would be the case with energization of the solenoids understood that energization of the solenoid 22 would cause somewhat lesser counterclockwise movement of'the printer wheel'than that shown in Figure 2, whereas energization of solenoids 23 or '24 would cause progressively lesser such move ment of the printer wheel. Energization of the solenoid 25Will cause-maximum movement of the printer wheel in a clockwise direction, whereas energ-ization of solenoids 23, 2'! or 23 will cause progressively lesser movement of the printer wheel in that direction: All'movements oi the base links l l'and l5 occur in opposition to the resilient action of the springs 58' or 2B, and those springs serve to immediately return the base links to'their normal positions upon deenergization of the solenoids.

By energizing the" proper one of the solenoids 2i to 23, the printer'wheel'may be moved to a position to present any desired printing charac ter to the printingzone 8': Preferably only one of the solenoids should be energized at any one time, although there may be some slight overlapping of'the intervals duringwhich the various solenoids are energized. The movement of the printer wheel 6 will occurvery rapidly and its position will be very precisely determined by the mechanism. The printer wheel will return to its neutral position as shown in Figure'l immediately upon-deenergization of the solenoids. 'Since the neutral position of the printer wheel is a po sition intermediate its other positions, it will be seen that the wheel canmove from the neutral position to any other desired position by traveling through a relatively small angle.

The embodiment of the invention illustrated in Figure 3 differs considerably in appearance from the arrangement described above but'it embodies the fundamental concepts of the invention. A base link 5! is oscillatable about a fixed axis 52. A similar base link 53 is osoillatable about a fixed axis 54. A fixed plate 55 is provided with slots 56 and 51 which form guideways for the free ends of the base links 5! and 53. The end 58 of the slot 56 forms a stop member which defines a normal position for the base link 5!.

22, 23 or 2Q: It will be readily The end 59 of the slot 51 forms a stop member which determines the normal position for the base link 53. The base links 5! and 53 are resilientlysbiased toward their normal positions by means or" the tension spring member 6'].

, An actuator link 51 is pivotally connected to the base link 5| at 62 and an actuator link 63 is pivotallyconnected to the base link 53 at 54. A pivot pin t5 pivotally connects the inner ends ofthe actuatorlinks 6! and 63. The pivot pin fifi'is slidably; received in a slot 6% of a lever 6'5. The lever 61 is pivotally mounted on a fixed axis :58 the end of-the lever opposite the slot 66 is fixedly secured by means of a suitable fastening means 69 to a suitable mechanical element such as a printingwheel-1B. The printing wheel 19 is oscillatable about the fixed axis 68.

A plurality of oscillatory motors l, i l are positioned adjaoentthe base link 5i at different distances from the fixed axis 52'. A plurality oisimilar oscillatory motors oscillatory motors are preferably electrically actuated and are identical in construction. The operation of the oscillatory motor will be described, it being understood that the other oscillatory motors operate in the same manner. The oscillatory motor ll has an arm lQwhich occu pies the position shown in: full lines when the motor is deenergized. Upon energization of the motor i! the arm 19* moves to-the dotted'line position 19'. Inso moving, the arm ilcauses the base link 53' to move to the dotted line position 53', the actuator link 63 to move to the dotted line position 6-3., and the lever 8'! to move to the dotted line position 61'; Movement of the lever 6'8 causes theprinter wheel iii to move to the dotted line position'l'fl; It'will be under-'- stood that energization of any other oscillatory motor will cause its associated base link tomove away from its respective'stop member, andthat the extent of movement of a base. linkwill be de pendent on the distance of the energized oscil latory motor from the'fixed axis about-which the base link operates; motors ii to '18, theprinter wheel ill'will be moved quickly and'accurately to any of its prescribed positions. been shown associated witheach base link, but this number can-be increased or decreased as required.

Attention should'be calledto the arrangement of the arms of the. oscillatory-motors ll to iii-rol ative'to the associated base links 5! and 53. By'

reference to the arm 19 of the motor ll it can be seen that initial clockwise movement of that arm will cause rapid initial movement of the base link 53; However, as the arm 19 approaches the dotted line position 79, the rate of movement of the base link 53 will be substantially lower. Thus the.

printer wheel'luwill'be given a rapid rate of initial movementand' this rate will gradually decelerate as the printer wheel approaches its prescribed position. This is a distinct advantage in that it eliminates the shock which would'result from sudden deceleration or sudden stopping of the printer wheel.

The form of the invention illustrated in Fig:- ure 4 embodies the fundamental conceptsoi the invention and additionally possessescertain advantages over the arrangements described above.

A base linkBll is 'osci-llatab'le abount' a fixed axis 8! and a base link 82 is oscillatable about a'fixed The-baselink 80 is provided with an axis 83.

'52, '53 and T5, 1E, H and 18" are positioned adjacent the base link 53'- at difierent distances from the fixed axis 5d. The

By energizing the proper Four: oscillatory motors have angularly extending arm 84 which is arranged to engage a fixed stop member 85 which determines the normal position of the base link 80. The base link 80 is biased to its normal position by means of the tension spring member 86. The base link 82 is provided with angularly extending portions 81 and B8. The angularly extending portion 87 is arranged to engage a fixed stop member 33 which determines the normal position for the base link 82. The base link 32 is biased toward its normal position by means of a tension spring member 90.

An actuator link 9| is pivotally connected to the base link 82 by means of a pin 92. An actuator link 93 is pivotally connected by a pin 94 to the base link 80. The actuator link 9| is pivotally connected to the actuator link 93 by means of the pivot pin 95. The actuator link 93 is shown as extending beyond the pivot pin 95 and as being connected by means of a pin 96 to a connector 97 which may lead to any mechanical element the position of which it is desired to control.

A plurality of oscillatory motors 500, I01, and I02 are positioned adjacent the base link 80 at different distances from the fixed axis 8|. Oscillatory motors I03, I64, I95 and IE6 are positioned adjacent the base link 82 at diilerent distances from the fixed axis 83. The motors IUI to I06, inclusive, may be the same as those described above in connection with the embodiment of the invention illustrated in Figure 3. It will be seen that energization of any of these motors will alter the position of the base link with which it is associated and that the position of the pivot pin 98 is controlled by the positions of the base links 80 and 82.

As indicated above, the embodiment of the invention illustrated in Figure 4 possesses advantageous characteristics which are not present in the forms of the invention described above. In the forms of the invention of Figures 1 to 3, movement of one of the base links of the mechanism creates no forces tending to move the other base link away from its stop member. For that reason, in the arrangements of Figures 1 to 3, either base link of the mechanism may be moved and there is no movement of the other base link of the mechanism. However, in the arrangement of Figure 4, movement of the base link 86 or the base link 82 sets up forces which tend to move the other base link from its normal position. This phenomenon has definite advantages in a rapidly operating mechanism such as is required in a printin machine operating at high speed. The tendency of the opposite base link to move in response to positive actuation of one of the base links is opposed by the inertia of such opposite base link and by the tension spring member tending to bias such opposite link toward its normal position. However, when one of the links is moved very quickly, the opposite link will overcome its own inertia and the effect of its biasing, and will momentarily move from its normal position, to be quickly returned, however, to such normal position by its biasing spring member.

The foregoing phenomenon may be understood by referring to the paths of movement of the pin 98 under various conditions of operation. If the base link 3i] is moved relatively slowly from its normal position shown in the drawing, the forces tending to move base link 82 will be insuificient to overcome the inertia of base link 82 and the action of spring member 99. Under such conditions, the base link 82 will not move and the pin 96 will follow the path designated by the dot- 1 independently oscillatable dash line H0. Similarly, when the base link 82 is moved slowly there will be no movement of the base link and the pin 96 will follow the dotdash line Ill. When the base link 80 is moved very suddenly from its normal position, there will be a momentary movement of the base link 82 from its normal position and the pin 96 will follow a path such as that illustrated by the dotted line i l2. Similarly, the imparting of very rapid and sudden motion to the base link 82 will cause momentary departure of the base link 80 from its normal position and the pin 96 will follow a path such as that illustrated by the dotted line H3.

The fact that rapid operation of the form of the invention illustrated in Figure 4 causes the pin 96 to follow the dotted line paths H2 01' H3 results in more gradual acceleration from rest of the mechanical element to which the connector 9! is attached. For the reasons pointed out above in the description of Figure 3, the oscillatory motors Hill to His, inclusive, impart rather rapid initial movement to the base links to and 82 followed by gradual deceleration of such movement. The more gradual acceleration resulting from the pin 96 following the paths H2 and H3 in combination with the gradual deceleration resulting from the particular arrangement of the oscillatory motors relative to the base links gives a very smooth operation which is free from excessively sudden accelerations or decelerations of the controlled element.

It will be seen from the foregoing detailed description that I have provided a variety of mechanisms capable of accomplishing the enumerated objects of the invention. The illustrated embodiments are to be considered as exemplary only and the broader scope of the invention is defined by the following claims.

Having thusdescribed my invention, I claim:

1. Mechanism for selectively moving a pivot pin to any of a plurality of prescribed positions on either side of an intermediate neutral position, comprising a pair of base links which are about fixed axes, stop means which determine definite normal positions for said base links, means for biasing said base links to engage said stop means, a pair of actuator links pivotally connected to said base links at points spaced from the said axes thereof, said actuator links being pivotally connected together by a pivot pin which occupies a definite neutral position when both of said base links are in their normal positions and which moves in one diree tion from said neutral position upon oscillation of one of said base links and in the opposite direction from said neutral position upon oscillation of the other of said base links, and means for independently oscillating said base links by con trolled amounts from their normal positions whereby said pivot pin may be selectively moved to prescribed positions on either side or" its said neutral position.

2. Mechanism for selectively moving a pivot pin to any of aplurality of prescribed positions on either side of an intermediate neutral position, comprising a pair of base links which are indeendently oscillatable about fixed axes, stop means which determine definite normal positions for said base links, means for biasing said base links to engage said stop means, a pair of actuator links pivotally connected to said base links at points spaced from the said axes thereof, said actuator links being pivotally connected together by a pivot pin which occupies a definite neutral position tion from said neutral position upon oscillation of one of said base linksand in the opposite direction from said neutral position upon oscill n of the other of said base links, and a pluralit or" solenoids positioned'along said base links at d ierent distances from said fixed axes, each aid solenoids being arranged; upon energization, to oscillate its associated base link frorn'its normal position by an amount dependent on the distance of such solenoidfrom ciated base link, whereby upon selective cation of such solenoids said pivot pin maybe see, lectively movedto prescribed positions on either side or" its said neutral position.

3. Mechanism as describedin claim 2 in Whic he said fixed axes of'said base links are coin cident.

4; Mechanism for selectively moving a pivot pin to any of a plurality of prescribed po on either side of an intermediate neutral position, comprising a pair of base links which are independently oscillatable about fixed axes, stop means which determine definite normal positions for said base links, means for biasing said base links toward said stop means, a pair of actuator links pivotally connected to said base links at points spaced from the said axes thereof, said actuator links being pivotally connected together by a pivot pin which occupies a definite neutral position when both of said base links are in "their normal positions-and which moves one direc tion from said neutral position upon oscillation of one of said base links and in the opposite di tion from said neutral position upon oscilla of the other of said base links, and a plurality of motors positioned along said base links different distances from said fixed axes, each oi said motors being arranged, upon energization, to oscillate its assoc'iatedbase link from its nor mal position by an amount dependent on the distance of such motor from the fixed axis of said associated base link, whereby upon selective energization of such motors said pivot pin may be selectively moved to prescribed positions on either side of its said neutral position.

5. Mechanism for selectively moving a pivot pin to any of a plurality of prescribed positions on either side of an intermediate neutral position, comprising a pair of base links which are independently oscillatable about fixed axes, stop means which determine definite normal positions for said base links, which normal positions are generally parallel, means for biasing said base links toward said step means, a pair of actuator links pivotally connected to said base links at points spaced from the said axes thereof, said actuator links being angularly disposed relative to each other and being pivotally connected together by a pivotpin which occupies a definite neutral position when both of said base links are in their normal positions and which moves in one direction from said neutral position upon oscillation of one of said base links and in the opposite direction of said neutral position upon oscillation of the other of said base links, and a plurality of oscillatory motors positioned along said base links at different distances from saidfixed axes, each of said motors being arranged, upon energization, to oscillate its associated base link from its normal position by an amount dependent. on t .9, distance of such motor from the fixed axis of when both of said base linksare in their normal positions and which moves in one directhe fixed axis or" said assosaid associated base link, whereby upon selective energization of such motors said pivot pin mayv be selectively moved to prescribed positions on either side of its said-neutral position.

6. Mechanism for selectively moving a pivot pin to any of a plurality of-prescribed positions on either sideofan intermediate neutral position, comprising a: pair of-baselinks which are independently oscillatable about fixed-axes, means for biasing'said base links against stop means which determine definite normal positions for said base links, a pair of actuator links pivotally connected said base links at points spaced-from they said fixed axes thereof, said actuator links being'pivotally connected together by apivot pin which woccupies'a definite neutral position when both .of said base links are in'their said normal positions, means for oscillating a-first' of said'base links by a definite amountfrom itsnormal position to,

thereby move said pivot pin to a prescribed positicn on one side of itsrsaid neutral position, and

means for oscillating thesecond of said base links by a definite amount'from its normal position to thereby move said pivot pin to a prescribed position on the opposite side-of its said neutral position.

'7. Mechanism comprising a pair of base links which are independently oscillatable about fixedaxes, said base links being biased toward definite normal positions, a pair of actuator links pivotally connected to saidbase links at points spaced from the said fixed axes thereof, said actuator links being pivotally connected together by a pivot pin which occupies a definite neutral position when both of said base links are in their saidnorinal positions, means for oscillating a first of said base links through a prescribed angle from itsnormal position to thereby move saidpivot pin to a definite first position in one direction from its said neutral position, and means for pivotally moving the second of'said base links through a prescribed angle from its normal position to thereby move said pivot pin to a definite second position in the opposite direction from its neutral position.

8. Mechanism for selectively moving a pivot pin to any of a plurality of prescribed positions on either side of an intermediate neutral position comprising a pair of base links which are independently oscillatable about fixed axes, stop means against which said base links may abut to define definite normal positions for said base links, a pair of actuator links pivotally connected to said base links at points spaced irorn the said fixed axes thereof, said'actuator links being pivotally connected together by a pivot pin which 0c cupies a definite neutral position when both of said base links are in their said normal positions, means for pivotally moving a first of said base links from its normal position to thereby move said pivot pin in one direction from its said neutral position, means for returning said first base link to its normal position to thereby return said pivot pin to its neutral position, means for pivotally moving the'second of said base links from its normal position to thereby move said pivot pin in the opposite direction from its said neutral position, and means for returning said second base link to its normal position to thereby again return said pivot pin to its neutral position.

No references cited. 

